T-bet and pSTAT-1 expression in PBMC from coeliac disease patients: new markers of disease activity

Expression analysis of IL-2, TBX21 and SOCS1 in peripheral blood cells of celiac disease patients reveals the diagnostic potential of IL-2

BACKGROUND

Celiac disease (CD) is a chronic immune-mediated enteropathy and a cytokine network is involved in its pathogenesis. Interleukin-2 (IL-2) has a key role in the adaptive immune pathogenesis of CD and has been reported to be one of the earliest cytokines to be elicited after gluten exposure by CD patients. This study aimed at investigating the expression level of IL-2 and functionally related genes SOCS1 and TBX21 in active and treated CD patients compared to controls.

METHODS AND RESULTS

Peripheral blood (PB) samples were collected from 40 active CD (ACD), 100 treated CD, and 100 healthy subjects. RNA was extracted, cDNA was synthesized and mRNA expression levels of the desired genes were investigated by Real-time PCR. The gene-gene interaction network was also constructed by GeneMANIA. Our results showed a higher PB mRNA expression of IL-2 in ACD patients compared to controls (p = 0.001) and treated CD patients (p˂0.0001). The mRNA expression level of TBX21 was also significantly up-regulated in ACD patients compared to controls (P = 0.03). SOCS1 mRNA level did not differ between active and treated CD patients and controls (p˃0.05) but showed a significant correlation with the patient's aphthous stomatitis symptom (r = 0.37, p = 0.01). ROC curve analysis suggested that the use of IL-2 levels can reach a high specificity and sensitivity in discriminating active CD patients.

CONCLUSIONS

The PB level of IL-2 has the potential to be introduced as a diagnostic biomarker for CD. Larger cohort studies, including pediatric patients, are needed to achieve more insights in this regard.

Proteins from Modern and Ancient Wheat Cultivars: Impact on Immune Cells of Healthy Individuals and Patients with NCGS

In non-celiac gluten sensitivity (NCGS), the elimination of wheat results in a clear symptom improvement, but gluten has still not been proven as (the sole) trigger. Due to the increase in the prevalence of gluten-related diseases, the breeding of high-performance wheat cultivars is discussed as a trigger. To analyze the immune stimulation and signal pathways, the immune cells of healthy subjects and patients with NCGS were stimulated with gliadins from wheat, and the expression and secretion of interleukin 1ß (IL1ß) and interleukin 6 (IL6) were studied. To determine the impact of wheat breeding, the monocyte cell line THP1 and human immune cells were stimulated with gliadin, glutenin, and albumin/globulin fractions of ancient and modern cereals, and expression of inflammatory molecules was checked. Immune cells of patients with NCGS showed an increased expression of IL1ß and IL6 after stimulation with gliadins compared to immune cells of healthy controls. Gliadins caused a strong activation of P-STAT3 in immune cells of healthy controls, and inhibitors of JAK and NFκB pathways considerably reduced this response. In addition to gliadins, we further showed that glutenins and albumin/globulins from all wheat cultivars from the last century, and especially from einkorn and spelt, also markedly induced the expression of inflammatory genes in THP1 and human immune cells. There was no correlation between enhanced immune stimulation and ancient or modern cultivars. This does not support the hypothesis that modern wheat breeding is responsible for the increase in gluten-related diseases. An altered immune situation is suggested in patients with NCGS.

Elevated interleukin-17A levels despite reduced microRNA-326 gene expression in celiac disease patients under gluten-free diet

Introduction: The microRNA-326 (miR-326) gene, by targeting ETS Proto-Oncogene 1 (ETS1), regulates the differentiation and interleukin-17A production of T helper 17 (Th17) cells. Celiac disease (CD) is an intestinal autoimmune disorder, in which the cascade of Th17 cells plays an important role in its pathogenicity. The aim of this study was to evaluate the expression changes of miR-326 and its two target genes ETS1 and IL-17A in celiac disease patients under a gluten-free diet (GFD). We expected the expression of miR-326 and IL-17A gene to decrease, and the expression of the ETS1 gene to increase, following the adherence to GFD.

Methods: Peripheral blood samples of 40 CD patients under GFD (for more than 1 year) and 40 healthy individuals were collected. RNA was extracted, cDNA was synthesized and the miR-326, ETS1 and IL-17A gene expressions were evaluated by the quantitative polymerase real-time qPCR method. P-value ˂ 0.05 was considered statistically significant.

Results: Although miR-326 mRNA expression was significantly lower in CD patients (P = 0.001), no significant difference was observed in ETS1 mRNA level between the two groups (P = 0.54), but IL-17A was significantly overexpressed in CD patients (P=0.002). No significant correlation was observed between the expression of the studied genes and the patientsʼ symptoms and Marsh classification.

Conclusion:Adherence to the GFD for one to two years did not have the expected effect on the expression of genes in this panel. The most important finding that contradicted our hypothesis was the observation of high IL-17A levels in CD patients despite dieting, which may be related to the protective effect of this cytokine on intestinal tight junctions, which needs to be confirmed in further studies.

Introducing New Potential Biomarkers for Celiac Disease among the Genes Extracted from General Databases

BACKGROUND: Inflammatory cytokines play roles in the pathogenesis of celiac disease. To introduce new diagnostic markers in patients with celiac disease for easy, fast, low cost, and non-invasive diagnosis, we evaluated the peripheral blood expression levels of interleukin-15 (IL-15), interleukin-17A (IL-17A), interleukin23A (IL-23A), granzyme B (GzmB), T-box transcription factor 21 (TBX21), and tumor necrosis factor alpha-induced protein 3 (TNFAIP3) of patients compared with the healthy controls, which were extracted from public databases organized in a protein-protein interaction network, in this group. METHODS: Peripheral blood mononuclear cells were collected from 30 patients with celiac disease and 30 healthy subjects. Total RNA was extracted, and mRNA expression levels of targeted genes were investigated by the quantitative real-time polymerase chain reaction (PCR) method. SPSS software was used for statistical analysis. Receiver operating characteristic (ROC) curve analysis was performed to characterize the diagnostic ability of the studied genes. RESULTS: The expression of IL-15, IL-17A, IL-23A, GzmB, TBX21, and TNFAIP3 genes in peripheral blood mononuclear cells of patients with celiac disease showed a significant increase compared with the control group. Among them, TNFAIP3, IL23A, and GzmB have better resolution and diagnostic value in differentiating patients with celiac disease from healthy controls. CONCLUSION: Our results suggest that TNFAIP3, IL23A, and GzmB could be useful and sensible markers in differentiating patients with celiac disease from healthy controls. However, the diagnostic relevance of other genes recognized by pathway analysis needs to be further investigated.

Evaluation of expression of common genes in the intestine and peripheral blood mononuclear cells (PBMC) associated with celiac disease

AIM

this study was conducted to investigate expression of the genes associated with CD in the target tissue in order to estimate contribution of each single gene to development of immune response. Then, the same set of genes was evaluated in peripheral blood mononuclear cells (PBMCs).

BACKGROUND

Celiac disease (CD) is a chronic systemic autoimmune disease of the small intestine occurring in genetically-susceptible individuals. There are several genes related to immune response.

METHODS

For this purpose, the genes related to CD were extracted from public databases (documents of proteomics and microarray-based techniques) and were organized in a protein-protein interaction network using the search tool for retrieval of interacting genes/proteins (STRING) database as a plugin of Cytoscape software version 3.6.0. The main genes were introduced and enriched via ClueGO to find the related biochemical pathways. The network was analyzed, and the most important genes were introduced based on central indices.

RESULTS

Among 20 CD genes as hub and bottleneck nodes, there were 7 genes with common expression in blood and intestinal tissue (C-X-C motif chemokine 11(CXCL11), granzyme B (GZMB), interleukin 15(IL-15), interleukin 17(IL-17A), interleukin 23(IL-23A), t-box transcription factor 21(TBX21), and tumor necrosis factor alpha-induced protein 3(TNFAIP3)).

CONCLUSION

The enriched biological process related to the central nodes of celiac network indicated that most of hub-bottleneck genes are the well-known ones involved in different types of autoimmune and inflammatory diseases.

The Role of Monocytes and Macrophages in Autoimmune Diseases: A Comprehensive Review

Monocytes (Mo) and macrophages (Mϕ) are key components of the innate immune system and are involved in regulation of the initiation, development, and resolution of many inflammatory disorders. In addition, these cells also play important immunoregulatory and tissue-repairing roles to decrease immune reactions and promote tissue regeneration. Several lines of evidence have suggested a causal link between the presence or activation of these cells and the development of autoimmune diseases. In addition, Mo or Mϕ infiltration in diseased tissues is a hallmark of several autoimmune diseases. However, the detailed contributions of these cells, whether they actually initiate disease or perpetuate disease progression, and whether their phenotype and functional alteration are merely epiphenomena are still unclear in many autoimmune diseases. Additionally, little is known about their heterogeneous populations in different autoimmune diseases. Elucidating the relevance of Mo and Mϕ in autoimmune diseases and the associated mechanisms could lead to the identification of more effective therapeutic strategies in the future.

Comparison of cytokine and gene activities in tissue and blood samples of patients with celiac disease

AIM

The aim of this study is to explore the expression of genes associated to celiac disease (CD) in the target tissue and peripheral blood monocytes (PBMC) or serum to introduce possible potential biomarkers.

BACKGROUND

Celiac disease (CD) is an autoimmune disease induced by gluten ingestion in genetically predisposed individuals. Despite technological progress, small intestine biopsy is still the gold standard for diagnosis of CD.

METHODS

CD data were collected from public databases (proteomics and microarray-based techniques documents). Differentially expressed genes (DEGs) in PBMC or serum as well as small intestinal biopsies from celiac patients compared to normal were collected and analyzed to introduce common individuals. Gene ontology was done to identify the involved biological terms.

RESULTS

Among 598 CD genes in biopsies and 260 genes in PBMC or serum, 32 common genes with a similar expression pattern in both sources were identified. A total of 48 biological terms were introduced which were involved in the CD via the determined DEGs. "Cytokine activity" was the most expanded one of the biological terms.

CONCLUSION

In this analysis, it was concluded that 32 potential biomarkers of CD can be assessed by complementary research to introduce effective and available biomarkers in biopsy and blood.

Influence of TBX21 T-1993C variant on autoimmune hepatitis development by Yin-Yang 1 binding

AIM

To investigated the mechanism of the association between the TBX21 T-1993C promoter polymorphism and autoimmune hepatitis type 1 (AIH-1) development.

METHODS

In vivo, In vivo, and reporter analyses were performed to determine the function of transcription factors binding to the T-1993C element of the TBX21 promoter in human CD4⁺ T and B cell lines. Flow cytometry and quantitative real-time PCR were used to analyze T-box transcription factor (T-bet) and interferon-γ (IFN-γ) expressions in CD4⁺ T cells, B cells and monocytes from the peripheral blood of AIH-1 patients including 5-1993TC and 15-1993TT genotype carriers, and healthy controls including 10-1993TC and 25-1993TT genotype carriers. Furthermore, a range of biochemical indices was measured simultaneously in the blood of AIH-1 patients.

RESULTS

TBX21-1993C allele created a strong Yin-Yang 1 (YY1)-binding site and decreased transcriptional activity of TBX21 promoter in human CD4⁺ T and B cells. Higher levels of T-bet and IFN-γ were detected in the circulating CD4⁺ T cells and B cells of AIH-1 patients carrying the TBX21-1993 TT genotype compared with the patients carrying the -1993 TC genotype and controls with the -1993 TC genotype. T-bet expression levels of circulating T cells and B cells were positively correlated with AIH-1 disease activity. Knockdown of YY1 with siRNA caused increased expression of T-bet and IFN-γ in peripheral blood mononuclear cells in AIH-1 patients.

CONCLUSION

The repression of TBX21 expression by high-affinity binding of YY1 to the -1993C allele may contribute to a decreased development of AIH-1 via suppression of type 1 immunity.

Enhanced Rg3 negatively regulates Th1 cell responses

Background

Korean Red Ginseng (KRG; Panax ginseng Meyer) is a widely used medicinal herb known to exert various immune modulatory functions. KRG and one of its purified components, ginsenoside Rg3, are known to possess anti-inflammatory activities. How they impact helper T cell-mediated responses is not fully explored. In this study, we attempted to evaluate the effect of KRG extract (KRGE) and ginsenoside Rg3 on Th1 cell responses.

Methods

Using well-characterized T cell in vitro differentiation systems, we examined the effects of KRGE or enhanced Rg3 on the Th1-inducing cytokine production from dendritic cells (DC) and the naïve CD4⁺ T cells differentiation to Th1 cells. Furthermore, we examined the change of Th1 cell population in the intestine after treatment of enhanced Rg3. The influence of KRGE or enhanced Rg3 on Th1 cell differentiation was evaluated by fluorescence-activated cell sorting, enzyme-linked immunosorbent assay, and quantitative real-time polymerase chain reaction.

Results

KRGE significantly inhibited the production level of IL-12 from DCs and subsequent Th1 cell differentiation. Similarly, enhanced Rg3 significantly suppressed the expression of interferon gamma (IFNγ) and T-bet in T cells under Th1-skewing condition. Consistent with these effects in vitro, oral administration of enhanced Rg3 suppressed the frequency of Th1 cells in the Peyer's patch and lamina propria cells in vivo.

Conclusion

Enhanced Rg3 negatively regulates the differentiation of Th1 cell in vitro and Th1 cell responses in the gut in vivo, providing fundamental basis for the use of this agent to treat Th1-related diseases.

Sarcoidosis in celiac disease: A page written by genetic variants in IL-18 miRNAs target site?

Sarcoidosis is a chronic idiopathic granulomatous disease. Interleukin-18 (IL-18) has been strongly implicated in the pathogenesis of sarcoidosis. Sarcoidosis shows characteristic microRNAs (miRNAs) profiles. MiRNAs have recently emerged as a new class of modulators of gene expression. MiRNAs are involved in susceptibility to a number of autoimmune diseases promoting and inhibiting the gene expression of different Th1 pro-inflammatory cytokines including IL18. Sarcoidosis has been connected with a variety of autoimmune disorders including celiac disease (CD). CD is a chronic, immune-mediated condition of the small intestine caused by permanent intolerance to dietary gluten. IL-18 has been reported to play an important role in inducing and maintaining inflammation after gluten exposure. MiRNAs expression is significantly altered in CD patients. We hypothesize that sarcoidosis and CD may be the result of common genetic variants in IL-18 miRNA target site.

Tupistra chinensis extract attenuates murine fulminant hepatitis with multiple targets against activated T lymphocytes

OBJECTIVES

The extract of Tupistra chinensis (TCE) is traditionally used for the treatment of inflammatory diseases in southwestern China for hundreds of years. The present study was designed to investigate the effects of the TCE against experimental hepatitis and to illustrate its potential mechanisms.

METHODS

Effects of TCE were investigated on Con A-induced hepatitis. Profiles of multiple cytokines were measured with biometric immuno-sandwich ELISA. Proliferation, activation and apoptosis of T lymphocytes were evaluated using Western blot, MTT analysis and flow cytometry.

KEY FINDINGS

TCE significantly inhibited levels of serum transaminases and lactic dehydrogenase in mice with Con A-induced hepatitis, accompanied with marked alleviation of the liver microscopic appearances. Moreover, it decreased levels of inflammatory cytokines in a concentration-dependent manner both in vivo and in vitro. It also suppressed mitogen-activated protein kinases and NF-κB-signalling in liver. These effects of TCE are attributed to its inhibition on activated T cells but not to hepatocytes protection. Flow cytometry and immunoblot assay data showed its effects on STAT1/NF-κB-signalling blockage and apoptosis induction in activated T cells.

CONCLUSION

Our findings illustrate the significant potential of TCE as a novel approach for treatment of T cell-mediated inflammatory diseases.

Expression patterns of Th1/Th2 transcription factors in patients with guttate psoriasis

Many lines of evidence propose that psoriasis is a T cell-mediated disease where T cell activation is followed by secretion of inflammatory cytokines. To elucidate the functional state of T cells in guttate psoriasis, we analysed mRNA expression levels of T-bet and GATA-3 for Th1 and Th2 differentiation, respectively together with Th1 (IFN-γ) and Th2 (IL-4) cytokine mRNA expression. Relative quantification of T-bet, GATA-3, IFN-γ and Th2, and IL-4 transcripts in peripheral blood leukocytes (PBL) was conducted by real-time reverse transcriptase PCR (RT-PCR). Serum levels of IFN-γ and Th2 and IL-4 were also determined by ELISA. GATA-3 and IL-4 mRNA expression levels were lower in psoriatic patients as compared to normal healthy controls. The expression levels of T-bet and IFN-γ and Th2 genes were relatively similar in the patients and controls. In addition, a marked decrease in plasma IL-4 levels was observed in the psoriasis group, while no differences were observed with regard to levels of IFN-γ and Th2 between patients and normal subjects. Furthermore, a clear correlation between decreased IL-4 mRNA expression and IL-4 (P < 0.05) was revealed. These results suggested that altered balance between Th1 and Th2 cells transcription factor genes and they products may be implicated in the pathogenesis of psoriasis.

Tissue-infiltrating lymphocytes analysis reveals large modifications of the duodenal "immunological niche" in coeliac disease after gluten-free diet

OBJECTIVES

The role of T lymphocytes in the pathogenesis of Celiac disease (CD) is well established. However, the mechanisms of T-cell involvement remain elusive. Little is known on the distribution of T subpopulations: T-regulatory (Treg), Th17, CD103, and CD62L cells at disease onset and after gluten-free diet (GFD). We investigated the involvement of several T subpopulations in the pathogenesis of CD.

METHODS

We studied T cells both in the peripheral blood (PB) and the tissue-infiltrating lymphocytes (TILs) from the mucosa of 14 CD patients at presentation and after a GFD, vs. 12 controls.

RESULTS

Our results extend the involvement of Treg, Th1, and Th17 cells in active CD inflammation both in the PB and at the TILs. At baseline, Tregs, Th1, and Th17 cells are significantly higher in active CD patients in TILs and PB. They decreased after diet. Moreover, CD62L+ TILs were increased at diagnosis as compared with GFD patients.

CONCLUSIONS

Our data show significant modifications of the above-mentioned subpopulations both in the PB and TILs. The increase of suppressive Tregs in active CD both in the PB and TILs is intriguing. T lymphocytes are known to have a crucial role in the pathogenesis of CD. We have shown that gluten trigger results in systemic recruitment of T lymphocytes, the unbalance between pro-inflammatory and anti-inflammatory populations and the increase of CD62L+ T cells in TILs. Our results delineate a more complete picture of T-cell subsets in active vs. GFD disease. Our data of T-cell subpopulations, combined with known data on cytokine production, support the concept that duodenal micro-environment acts as an immunological niche and this recognition may have an important role in the diagnosis, prognosis and therapeutical approach of CD.

Inhibition of CXCL10 release by monomeric C3bi and C4b

Cellulose acetate (CA) beads are often used for leucocyte apheresis therapy against inflammatory bowel disease. In order to clarify the mechanism of the anti-inflammatory effects of CA, global analysis of the molecules generated in blood by the interaction with CA beads was performed in this study. An activated medium was collected from whole blood that had been preincubated with CA beads, and the effects of the CA-activated medium on leucocyte function were investigated. Fresh blood was stimulated with lipopolysaccharide (LPS) or interferon (IFN)-β in the presence of the activated medium, and levels of chemokines and cytokines, including CXCL10 (IFN-inducible protein-10), and phosphorylated STAT1 (signal transducer and activator of transcription 1), which is known to be essential for CXCL10 production in leucocytes, were measured. IFN-β- or LPS-induced CXCL10 production, expression of CXCL10 mRNA and phosphorylation of STAT1 were significantly reduced in the presence of the medium pretreated with CA beads compared with the control without the CA bead treatment. The factors inhibiting CXCL10 production were identified as the C3 and C4 fragments by mass spectrometry. The monomeric C3bi and C4b proteins were abundant in the medium pretreated with CA beads. Furthermore, purified C3bi and C4b were found to inhibit IFN-β-induced CXCL10 production and STAT1 phosphorylation. Thus, STAT1-mediated CXCL10 production induced by stimulation with LPS or IFN was potently inhibited by monomeric C3bi and C4b generated by the interaction of blood with CA beads. These mechanisms mediated by monomeric C3bi and C4b may be involved in the anti-inflammatory effects of CA.

Advances in celiac disease

PURPOSE OF REVIEW

To critically summarize recent research in celiac disease.

RECENT FINDINGS

There are new serological markers with potential use not only in the diagnosis of celiac disease but also as important follow-up tools. As our understanding of celiac disease increases with further isolation of nonhuman leukocyte antigen genes and clarification of the intracellular pathways that underlie its pathogenesis, there are new modalities which will not only allow improved risk stratification of individuals but also facilitate the development of novel therapeutic agents.

SUMMARY

Small bowel biopsy remains the gold standard for both diagnosis and monitoring. A gluten-free diet currently remains the only treatment option, with potential other options being discovered such as glutenases for predigestion of gluten.

Characterization of gliadin-specific Th17 cells from the mucosa of celiac disease patients

OBJECTIVES

Celiac disease (CD) is a disorder characterized by a deregulated immune response to ingested wheat gluten and related cereal proteins in susceptible individuals. It has been considered that the onset of CD is mediated by a skewed Th1 response. However, the participation of Th17 cells in the pathogenesis of the disease, a key cell population in other autoimmune disorders, has not been studied in detail. We have investigated the presence of Th17 cells in the mucosa of active CD patients and their functional implications in the pathogenesis of the disease.

METHODS

T cells obtained from duodenum biopsies from 15 untreated patients and 11 control individuals were characterized by flow cytometry, immunoassays, and real-time PCR.

RESULTS

We found gliadin-specific CD4(+) interleukin (IL)-17A-producing T cells in the mucosa of CD patients with a phenotype consisting of TCR (T-cell receptor)αβ(+) CD45RO(+) CD161(+) CCR6(+) (C-C chemokine receptor type 6) and IL-23R(+). Functional analysis showed that Th17 cells from CD patients are different from those of control individuals in terms of cytokines production. Th17 cells from CD patients, but not from controls, simultaneously express transforming growth factor-β (TGFβ). Th17 CD cells also produce interferon-γ (IFNγ), IL-21, and IL-22. The analysis of the transcription factors revealed a high expression of interferon regulatory factor-4 as a feature of gliadin-specific cells from CD patients with respect to controls.

CONCLUSIONS

Gliadin-specific Th17 cells are present in the mucosa of CD patients having a dual role in the pathogenesis of the disease as they produce proinflammatory cytokines (such as IL-17, IFNγ, IL-21), mucosa-protective IL-22, and regulatory TGFβ, which actively modulates IL-17A production by T cells in the celiac mucosa.

Transcriptional regulation of the mucosal immune system mediated by T-bet

The immune system faces the arduous task of defending the mucosal surfaces from invading pathogens, but must simultaneously repress responses against commensal organisms and other inert antigens that are abundant in the external environment, as inappropriate immune activation might expose the host to increased risk of autoimmunity. The behavior of individual immune cells is governed by the expression of transcription factors that are responsible for switching immune response genes on and off. T-bet (T-box expressed in T cells) has emerged as one of the key transcription factors responsible for controlling the fate of both innate and adaptive immune cells, and its expression in different immune cells found at mucosal surfaces is capable of dictating the critical balance between permitting robust host immunity and limiting susceptibility to autoimmunity and allergy.

Flow cytometry of intestinal intraepithelial lymphocytes in celiac disease

This article reviews the multiple uses of flow cytometry in the diagnosis, monitoring and research of celiac disease, the most prevalent chronic autoimmune gastrointestinal disease. The phenotyping of intraepithelial lymphocytes (IELs) is of clinical relevance in the diagnosis of the disease given the characteristic features of elevated CD3+ IELs (αβ and γδ TcR) and the decrease in CD3- IELs. IEL biomarkers are also useful in the assessment of the response to the gluten-free diet and, importantly, in the diagnosis of the severe complications of celiac disease: refractory celiac disease and enteropathy-associated T-cell lymphoma. Novel applications of flow cytometry for the detection of anti-transglutaminase antibodies (a validated biomarker of celiac disease) and of gluten (the triggering antigen of the autoimmune process) are also discussed. The assessment of diagnostic and prognostic biomarkers by flow cytometry in celiac disease is performed routinely in a growing number of centers and it is an example of the versatility of this technique and its applicability to the research and clinical study of solid tissues.